Contradictions do not exist. Whenever you think that you are facing a contradiction, check your premises. You will find that one of them is wrong.
(Part I, 7)

John Galt is Prometheus who changed his mind.
(Part II, 5)

I swear by my life and my love of it that I will never live for the sake of another man, nor ask another man to live for mine.
(Part III, 1)

We are those who do not disconnect he values of their minds from the actions of their bodies.
(Part III, 3)

For twelve years, you have been asking: Who is John Galt? This is John Galt speaking. I am the man who loves his life. I am the man who does not sacrifice his love or his values. I am the man who has deprived you of victims and thus has destroyed your world, and if you...
(Part III, 7)